Download Air Masses and Fronts

Air Masses and Fronts
Chapter 16 section 2
S6E4.b – Relate unequal heating of
land and water surfaces to form
large global wind systems and
weather.
S6E4.c – Relate how moisture
evaporating from the oceans affects
the weather patterns and the
weather events such as hurricanes.
Air Masses
Air mass – is a large body of air where
temperature and moisture content are
similar throughout.
 Moisture content and temp are determined
by the area over which the air mass forms
called source regions.
 Represented on maps by two-letter symbols;
first letter – moisture content, second letter temperature
Symbols
• C- continental; forms over land; dry
• M – maritime; forms over water; wet
• P – forms over the polar regions; cold
• T – develops over the Tropics; warm
Cold Air Masses (3)
• Continental polar (cP)- • air mass forms over
northern Canada, brings
extremely cold winter
weather to the US,
summer brings cool, dry
weather.
Cold Air Masses
Maritime polar (mP)
Forms over the North Pacific
(Forms in 2 places) Ocean; cool and very wet,
brings rain and snow to the
Pacific Coast in winter, foggy
weather in summer.
Forms over the North Atlantic
Ocean brings in cool, cloudy
weather and precipitation to
New England in the winter, cool
weather for in the summer.
Warm Air Masses (3)
• Maritime tropical
(mT)
• Develops over warm
areas in the Pacific Ocean
and Atlantic Ocean.
• Winter, they bring mild,
often cloudy weather.
Summer, hot and humid
weather, hurricanes, and
thunderstorms.
Warm Air Masses
• Continental tropical
(cT)
• Forms over the deserts
of northern Mexico and
the southwestern United
States
• moves northward and
brings clear , dry, and hot
weather.
Review
1. What are the major
air masses that
influence the
weather in the
United States?
2. What is one source
region of a
maritime polar air
mass?
1. Continental polar,
maritime polar,
maritime tropical,
and continental
tropical.
2. The North Pacific
and the North
Atlantic Oceans.
Review
3. Why does the Pacific
Coast have cool, wet
winters and warm, dry
summers?
3. Cool, wet winters
are affected by a
maritime polar air
mass.
Summers are affected
by a dry continental
air mass.